Esters of 10, 11-di (alkylcarbonyloxy) hendecanoic acid



. 10,1l-diacetoxyhendecanoate, when tested comparison with Sancticizer M-17 phthalyl ethyl glycolate), produces cellulose ace- Patented June 6, 1950 ESTERS OF 10,11-DI(ALKYLCARBONYLOXY) HENDECANOIC ACID Bay A. Clarke, Staunton, Va., assignor to Hercules Powder Company, Wilmington, Del., a corporation of Delaware No Drawing. Application December 26, 1947, Serial No. 794,100

4 Claims.

This invention relates to new compositions of matter which are derivatives of lO-hendecanoic acid and. to methods for preparing the same. More particularly, it relates to derivatives of hendecanoic acid which are particularly useful as plasticizers for cellulose derivatives and to methods for preparing the same.

The compounds prepared in accordance with this invention have the following general formula:

wherein R1 may be any alkyl or alkoXy-substituted alkyl group of from 1 to 8 carbon atoms and wherein R2 and R3 may be any alkylcarbonyloxy group containing from 2 to 4 carbon atoms, i. e., acetoxy, propionoxy, etc. These compounds are prepared preferably by esterifying IO-hendecanoic acid (undecylenic acid) with the desired alcohol, then hydroxylating the alkyl hendecanoate, and finally acetylating, propionylating, etc. the product to yield a completely acetylated or propionylated, etc. derivative. In this manner, methyl 10,1l-diacetoxyhendecanoate, ethyl 10,11- diacetoxyhendecanoate, propyl 10,11-.dipropionoxyhendecanoate, etc. may be prepared.

The compounds have an interesting and useful property in that they possess an unusually high solvent power for cellulose derivatives in general and cellulose acetate in particular. At the same time, they are in the class of substantially nonvolatile plasticizers and hence can be used in the preparation of free films and coating compositions with excellent results. Possessing such high solvent power for cellulose acetate,.these compounds used in conjunction with cellulose acetate "are productive of free films and coatings having an exceedingly high flexibility as'is evidenced .by the results obtained using the M. I. T. folding Thus, the compound, methyl in (methyl endurance test.

tate film having a flexibility 'over 2 times as great. Sancticizer M-l'? is a commercial plasticizer for cellulose acetate of the nonvolatile type which is about the best commercially available from the standpoint of providing flexibility. The

atoms and'Rz and R3 contain 2 carbon atoms 2 each are preferred for use with cellulose acetate, although any of the compounds as broadly defined may be so used. Examples of the preferred compounds are methyl 10,11-diacetoxyhendecanoate; ethyl 10,1l-diacetoxyhendecanoate; 2-methoxyethyl 10,ll-diacetoxyhendecanoate; 2-ethoxyethyl 10,1l-diacetoxyhendecanoate, etc; Compounds of the above general formula wherein R1 contains from 5 to 8 carbon atoms and R2 and R3 each contain more than 2 carbon :atoms are preferred as plasticizers for nitrocellulose and ethyl cellulose, although here again any of the compounds as broadly defined may be so used. Examples of such preferred compounds are amyl 10,11-dipropionoxyhendecanoate; hexyl 10,1l-dipropionoxyhendecanoate; amyl 10,11-dibutyroxyhendecanoate, etc.

Having now indicated the nature of the invention, the following examples are given in illustration of certain preferred embodiments.

Example 1 alyst. The ester is purified by distillation in vacuo. It boils at 127-135 C. at 13 mm. pressure.

A mixture of 1260 parts of glacial acetic acid and 342 parts of aqueous 30% hydrogen peroxide is heated on a steam bath at Bil-85 C for /2 hour. The mixture is cooled to room temperature, and 396 parts of the methyl hendecanoate are added with vigorous stirring. The solution is gradually warmed until an exothermic reaction is observed. After standing overnight, the mixture is warmed to 65 0., held at 65 C. for 4 hours, and then allowed to stand for a day at room temperature. The reaction mixture is poured into 2000 parts of water and the resulting oily layerseparated. The aqueous layer is extracted with ethyl ether and the ethereal solution added to the oily layer. The resulting ethereal solution is washed with water until free of acid, dried and the solvent distilled in vacuo to give 413 parts of product. To insure complete hydroxylation of the methyl hendecanoate, the product is again treated with the same reactants only in lesser quantities (630 parts of glacial acetic acid and 171 parts of aqueous 30% hydrogen peroxide) following the procedure described above. The final product isolated weighed 419 parts.

tion mixture is poured into the water with stirring. The product is recovered by extraction with benzene. The benzene extract is washed with hot water, saturated sodium carbonate and again with hot water. The neutral solution is dried with anhydrous sodium sulfate and the benzene distilled therefrom at about 20 mm. pressure to give 443.5 parts of crude acetylated product. This crude product is vacuum distilled at 1.5 mm. and that portion of the charge distilling at 166.5-1'74" C. collected. This amounted to 62.6% of the charge.

This product had a saponification number of 522 and a per cent methoxyl of 9.64. It exhibited excellent solvent power for cellulose acetate and was compatible with both laquer and plastic types of cellulose acetate at ratios of 1:1 and 2:1 cellulose acetate to plasticizer. Plasticized films resulting from the use of the 2:1 ratio were clear and extremely flexible. It was also compatible with nitrocellulose and ethyl cellulose, yielding very flexible films.

A sample of the methyl 10,11-diacetoxyhende- 'canoate prepared as above can be further purifled by dissolving 145.3 parts thereof in 200 parts of hexane, and washing with two 150 part portions of aqueous 5% sodium bicarbonate solution, six 150 part portions of 10% sodium carbonate solution, and then with water until the aqueous iayer is neutral. The hexane solution is filtered, decoliorized with 5 parts of activated carbon (Darco) and 5 parts of acid activated earth made from montmorfillonite (Filtrol) and dried with 19 parts of anhydrous calcium sulfate. The

clear hexane solution is then distilled to remove the hexane and the product (131.8 parts) is vacuum distilled to give 98.9 parts of product boiling at 150-157 C. at 0.5 mm. of mercury.

This purified product was found to possess excellent solvent power for cellulose acetate, being compatible with both lacquer and plastic grades of cellulose acetate at ratios of 1:1 to 2:1 cellulose acetate to plasticizer. Cellulose acetate films prepared on the basis of the latter ratio were clear and very flexible. The product was also found to be compatible over wide ranges with ethyl cellulose and nitrocellulose.

Example 2 The purified colorless sample of methyl 10,11-

were evaluated on a M. I. T. folding endurance a tester and were held under 200 grams tension during the test. The following results were obtained:

Films ilasticized Withgg Pt gg g Methyl 10,l1-fiiacetoxyhendecanoate .i 1, 65031480 Methyl phthalyl ethyl glycolate 640;};195

From the above data it can be seen that the films containing the methyl 10,'1l-diacetoxyhendecanoate had over 2 times the flexibility of the films containing methyl phthalyl ethyl glycolate.

Example 3 Ethyl hendecanoate is prepared by refluxing a mixture of lll-hendecanoic acid and ethanol containing anhydrous hydrogen chloride as the catalyst. The ester is purified by distillation in vacuo. The purified ethyl hendecanoate is hydroxylated using glacial acetic acid and hydrogen peroxide in accordance with Example 1. The hydroxylated product is then acetylated by refluxing with acetic anhydride to form ethyl 10,11- dia'cetoxyhendecanoate. This product has excellent solvent power for cellulose acetate, also for ethyl cellulose and nitrocelluose.

Example 4 Propyl hendecanoate is prepared by refluxing a mixture of 10-h'endecanoic acid and n-propanol containing sulfuric acid as the catalyst. The ester is purified, as indicated in Example '1, by distillation in vacuo. The purified propyl hendecanoate is hydroxylated using glacial acetic acid and hydrogen peroxide in accordance With Example 1. The hydroxylated product is then acetylated by refluxing with acetic anhydride to form propyl 10,11-diacetoxyhendecanoate. This product is found to be an excellent plasticizer for cellulose acetate, yielding very flexible films. It is also compatible with nitrocellulose and ethyl cellulose over a wide range of proportions.

Example 5 2-methoxyetlranol hendecanoate is prepared by refluxing a mixture .of lfl-hendecanoic acid and 2- neth'oxyethanol (Methyl Cellosolve) and continuously removing water formed by the reaction. The ester is purified by distillation in vacuo as in Example '1. The purified Z-methoxyethyl hendecanoate is hydroxylated using glacial acetic acid and hydrogen peroxide as shown in Example 1. The hydroxylated product is then butyrated by refluxing with butyric anhydride to form Z-metho'xyethyl '10,'l1-dibutyroxy hendecanoate. This product has excellent solvent power for cellulose acetate and for both nitrocellulose and ethyl cellulose.

In the examples given, the preparation of the allryl or alkoxyalkyl ester of IO-hendecanoic acid is the first step in preparing the compounds of this invention, followed by hydroxylation and. then acetylation, propionylation, etc. of the hydroxylated ester. This stepwise procedure is preferred; however, the esterification of the acid group of the h'endecanoic acid may be effected after hydroxylation of the acid or even after both hydroxylation and acetylation, propionylation, etc. have been 'efiected. If esterification is 'effected after acetylation, propionylation, etc., special techniques may be required due to ester interchange reactions taking place.

The esterification of the acid group of 10- hendecanoic acid may be accomplished by methods known to the art. Preferably, this is accomplished at reflux temperature which is dependent on the boiling point of the alcohol used. Any monohydric alcohol of from 1 to 8 carbon atoms may be employed as for example methyl, ethyl, propyl, butyl, etc. alcohol, Z-methoxyethanol, :2-ethoxyethanol, etc.

'1 The .hydroxylation of IO-hendecanoic acid or ample, concentration of the hydrogen peroxide employed, proportion of reactants, etc. The reaction time varies from about 2 to 24 hours dependin on the temperature employed. If the reaction mixture is maintained at the higher temperatures the time required for complete reaction will be shorter. The product can be recovered from the reaction mixture in the manner shown in the examples by taking advantage of its being substantially insoluble in water.

Although hydroxylation of the 10-hendecanoic acid or ester thereof using glacial acetic acid and hydrogen peroxide is preferred, other means of hydroxylating aliphatic organic compounds having a C=C group may be employed. Thus, for example, the hydroxylation can be efiected with alkaline potassium permanganate at low temperatures (0 0.), with osmium tetroxide in ether solution or by controlled oxidation with air or oxygen in an aqueous medium.

The product of the hydroxylation reaction is acetylated, propionylated, etc., preferably by refluxing with the corresponding acid anhydride, using an excess of the acid anhydride. However, any other method of effecting acetylation, propionylation, etc., may be employed if desired such as by the use of acid chlorides (such as acetyl chloride) or ketene.

It will be understood that compounds havin excellent plasticizing properties for cellulose derivatives may be prepared in accordance with this invention in which R2 and R3, referring to the general formula, are the same or difierent alkylcarbonyloxy groups. A compound in which different alkylcarbonyloxy groups are present can be prepared, for example, by partially combining the hydroxylation and acetylation steps by co-oxidizing a mixture of an alkyl hendecanoate and an aldehyde with air or oxygen. Thus, the co-oxidation of methyl hendecanoate and acetaldehyde gives methyl hydroxyacetoxyhendecanoate. onylated to yield methyl propionoxyacetoxyhendecanoate.

The products obtained in accordance with the processes described hereinabove are colorless,

This compound can then be propimobile liquids which are unique in that they possess an unusually high solvent power for cellulose derivatives, particularly nitrocellulose, ethyl cellulose and cellulose acetate. At the same time, these compounds fall in the class of nonvolatile plasticizers for these cellulose derivatives. Hence, they are especially well suited for use in plastics and coating compositions containing the aforesaid cellulose derivatives. Films and coatings prepared from such compositions have an unusually high degree of flexibility as is evidenced by comparative tests described previously.

All parts, proportions and percentages in this specification and claims are by weight unless otherwise indicated.

What I claim and desire to protect by Letters Patent is:

1. As a new composition of matter, a compound having the formula oHr-oiztroHmcooR,

I... wherein R1 is selected from the class consisting of alkyl and alkoxyalkyl groups of not more than 8 carbon atoms and R2 and R3 are alkylcarbonyloxy groups of from 2 to 4 carbon atoms.

2. As a new composition of matter, methyl 10,1l-diacetoxyhendecanoate.

3. As a new composition of matter, ethyl 10,11- diacetoxyhendecanoate.

4. As a new composition of matter, propyl 10,1l-diacetoxyhendecanoate.

RAY A. CLARKE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,927,295 Powers Sept. 19, 1933 2,007,968 Graves July 16, 1935 2,031,227 Pevere Feb. 18, 1936 2,050,927 De Groote Aug. 11, 1936 2,212,385 Brod Aug. 20, 1940 2,240,437 Colbeth Apr. 29, 1941 2,256,353 Rheineck et a1. Sept. 16, 1941 2,332,849 .Gruber et al. Oct. 26, 1943 2,385,359 Hunter et al. Sept. 25, 1945 2,443,280 Swern et al. June 15, 1948 2,445,911 Fisher July 27, 1948 FOREIGN PATENTS Number Country Date 402,262 Great Britain Nov. 30, 1933 Certificate of Correction Patent No. 2,510,802 June'fi, 1950 RAY A. CLARKE It is hereby certified that errors appear in the printed specification of the above numbered patent requirlng correctlon as follows:

Column 1, line 11, for that portion of the formula reading CH read 0H,; column 2, line 31, after SO-85 insert a period column 3, line 16, for laquer read lacquer; column 4, line 19, for mtrocelluose read nitrocellulose;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Ofiice. Signed and sealed this 19th day of September, A. D. 1950.

THOMAS F. MURPHY,

Assistant Gammissiofler of Patents. 

1. AS A NEW COMPOSITION OF MATTER, A COMPOUND HAVING THE FORMULA 